Tool for laying conduits for electrical conductors.



No. 644,794. Pa'tentad Mar. 6, |900. J. F.' CUMMINGS.

TOL FUR LAYING GDNDUITS FUR ELECTRICAL CUNDUGTORS. (Application med my 22, 189m (No Model.)

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Miren STATES ATENT OFFICE.

JAMES F. OUMMINGS, OF DETROIT, MICHIGAN, ASSIGNOR TO T I-IE AMERI- CAN VITRIFIED OONDUIT COMPANY, OF NEW YORK, N. Y.

TOOL FOR LAYING CONDUITS FOR ELECTRICAL CONDUCTORS.

SPECIFIGAIFION forming part of Letters Patent No.6/.-l4=,'794,` datedMarch 6, 1 900.

Application filed July 22, 1899i` Se1ial-No.'724,'77'?. (No model.)

To all whom t may concern;

Be it known that I, JAMES F. CUMMINGs, a citizen of the UnitedStates, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Tools for Laying Conl duits for Electrical Conductors, of which the IOV following is a specication, reference being had therein to the accompanying drawings.

The invention relates to tools for laying tile conduits for electrical conductors.

It is the object of the invention to secure a more accurate alinement of the conduitsections with each other and to remove the cement which passes through the joint between the sections, so that the interior of the conduit when finished will be smooth and unbroken.

In the laying of tile conduits for the purpose described it is customary to embed the sections in cement. To secure accurate alinement of each of the sections, it is necessary to employ a tool or mandrel which bridges the joint between the sections and holds them in proper relation. These tools as heretofore made consist of an elongated body of substantially the bore of the conduit, beingprovided with a handle at its forward end for drawing it through the conduit-section. The objection to such construction is that in the use of the tool the wear of the body soon reduces its diameter, so that it no longer accurately fits the bore of the conduit-sections, and consequently the latter are not accurately alined.

It is one of the objects of my invention to provide means whereby the tool may be maintained the proper size7 and, further, to provide means for more thoroughly cleaning the joint between sections.

The invention therefore consists in the construction, arrangement, and combination of parts, as hereinafter more fully described and claimed.

In the drawings, Figure l is a vertical longitudinal section through a conduit, showing in elevation my tool 'as in use therein. Fig. 2'is a cross-section on line a; cc, Fig. l. Figs.

3, 4, and 5 are views similar to Fig. 1, showing modifications.

As shown in Figs. l to 4:, my tool comprlses,

essentially, a central stem A and a surrounding helix B, secured at its opposite ends to said stem and adapted to fit the bore of the conduit: This structure may be formed either as shown in Figs. l and 3, where the stein and helix are bent from a single rod, or as shown in Fig. et, where they are formed from separate rods. With both constructions the stem serves to hold the coils of the helix in alinement with each other, or, in eect, to produce a cylindrical body which is of a diameter to fit theconduit and preferably of a length somewhat greater than that of one of the conduit-sections.

, With the tool constructed as thus far described in the operating of laying the conduit the tool is placed in oneof the conduitsections, which is then laid imposition in the cement. Other sections are then laid successively, and as each new one isv placed in position the operator draws the tool along.

It will be readily understood that as the diameter of the helix is such as to lit the bore of the conduit sections the latter will be brought into alinement by the drawing of the thereof are preferably of a spiral form, thus making a tapering nose to the helix.

In Figs. 3 and 4t I have shown a construction in which a brush D is placed upon the stem between two sections of the helix,which brush forms an additional wiper for the joint. The two sections of thehelix are, in the construction shown in Fig. 3, formed of a single rod, of which the central'portion forms the stem and the end portion of the helices.

In Fig. 5 I sho-w a construction in which the tool is composed of a central stem A and a series of disks E, secured thereon and spaced from each other by the intermediate sleeves or collars F, the parts being secured in position by a clamping-nut G at the end of the IOO stein. In this construction, as in those previously described, the disks foi-1n a series of spaced Scrapers fitting the bore of the conduit and serving to both aline the sections and Wipe the joint.

What I claim as my invention is- 1. A tool for laying conduit for electrical conductors comprising a central stem and a non-collapsible alinin g and scraper helix surrounding and iixedly secured to said stern of a size to tit the bore of the conduit.

2. A tool for laying conduits for electrical conductors comprising a central stein and a surrounding helix formed of asingle rod substantially as and for the purpose described.

3. A tool for laying` conduits for electrical conductors, comprising a central stern, two

helices surrounding said stein and a brush arranged on said stem between the helices substantially as and for the purpose described.

4. A tool for laying conduit for electrical JAMES F. CUMMINGS.

Witnesses:

M. B. ODOGHERTY, H. C. SMITH. 

